Enhancement of silicon-wafer solar cell efficiency with low-cost wrinkle antireflection coating of polydimethylsiloxane

A low-cost antireflection (AR) coating of polydimethylsiloxane (PDMS) with wrinkle surface structure is demonstrated. The surface modulations with controllable amplitude and period are experimentally performed by plasma surface oxidation of a pre-stretched PDMS followed by removal of the applied mechanical strain. The period and the aspect ratio of the PDMS wrinkle are dependent on plasma treatment time in the process of surface modification. Compared with the solar cell without a wrinkle coating, the demonstrated PDMS wrinkle coating can improve the efficiency of actual commercial silicon-wafer solar cells, especially at large angles of incidence. Intriguingly, the all-day average relative efficiency of the cell with PDMS wrinkle is improved by approximately 13.6%.